I was just wondering why would a Sr. Member will scam a 90-100$ amount

Some people has nothing to do with their ranks, as their main target is to get some money. No matter how. His 250 merits were air-dropped, and the other 100+ merits he earned in the last couple of years. When you see people not in a signature campaign and unable to earn ten merits in the last 120 days, they are unlikely to get hired by any campaign managers.
So if they didn't get any chance in any campaign, there is no money, and the account has no value. It's not safe to sell accounts as well. So, assume he destroyed his account for that $90. At least he was able to get some money. Sorry for your loss Royse777